In liquid processing industry, such as food processing, mixers are widely used for providing an efficient mix of liquids with solid and/or gaseous contents. Within this technical field it is common to classify the available mixers into i) batch mixers or ii) inline mixers. Typically, a batch mixer operates by circulating the media to be mixed within a tank and it is often a preferred choice for high viscous fluids. Inline mixers are typically operating in a different manner, in which the fluids are circulated outside the tank for continuously mixing liquid. As compared with batch mixers, inline mixers are often preferred for low viscous liquids and for large volume production.
The pumping ability of existing in-line mixers and especially existing in-line high-shear mixers is significantly reduced when the liquid viscosity is increased. At viscosities above 1000 cP their pumping ability is often completely lost, in particular if their pump performance is based on the centrifugal principle. Today this limits the use of inline mixers to mixing applications for relatively low viscous fluids.
In liquid processing applications it is important to reduce the manufacturing costs for the liquid processing equipment. However, the process of mixing additives into liquids in an in-line mixer comes with a number of considerations which need to be dealt with. One requirement is the provision of a vacuum in order to suck in the additives into the liquid. It is also required to provide a mixer which allows pumping of liquids containing un-dissolved gases and powders. A yet further requirement is associated with high viscosity liquids since such liquids normally must be handled by complex and expensive positive displacement pumps. In addition to this, a liquid processing mixer should also be capable of providing a high shear mixing.
In view of this there is a need for an improved liquid processing mixer, which is capable of handling a wide range of liquid products. Such mixer should have a simple mechanical design and it should require a reduced physical footprint.